Tapered roller retainer and method of bearing assembly

ABSTRACT

A tapered roller retainer for tapered roller bearings in which the retainer is a one-piece molded body having a single flange supporting roller cage fingers. The roller cage fingers form reverse tapered pockets for the tapered rollers and the body of the retainer is sufficiently resilient to permit flexing of the cage fingers to facilitate insertion of the tapered rollers. The flexing of the tapered roller retainer with the reverse tapered roller pockets improves and facilitates bearing assembly methods.

White ates Dominik 51March 13, 1973 TAPERED ROLLER RETAINER AND ETHOD OFBEARING ASSEMBLY [75] Inventor: Erich Dietmar Dominik, Canton,

Ohio

[73] Assignee: The Timken Company, Canton,

Ohio

[22] Filed: April 5, 1971 [21] Appl. No.: 131,282

[52] 11.8. CI ..308/214 [51] Int. Cl ..Fl6c 33/00, F16c 19/00 [58] Fieldof Search ..308/2l4, 217

[56] References Cited UNITED STATES PATENTS 2,435,839 2/1948 McNicoll..308/2l8 3.075,278 l/l963 Bratt ..308/2l7 FOREIGN PATENTS ORAPPLICATIONS 211,182 7/1966 Sweden ..308/2l4 Primary Examiner-Charles J.Myhre Assistant Examiner-Frank Susko Attorney-Gravely, Lieder & Woodruff[57] ABSTRACT A tapered roller retainer for tapered roller hearings inwhich the retainer is a one-piece molded body having a single flangesupporting roller cage fingers. The roller cage fingers form reversetapered pockets for the tapered rollers and the body of the retainer issufficiently resilient to permit flexing of the cage fingers tofacilitate insertion of the tapered rollers. The flexing of the taperedroller retainer with the reverse tapered roller pockets improves andfacilitates bearing assembly methods.

4 Claims, 7 Drawing Figures SJZOASO PATENTEUHAM 3mm SHEET 10F 2PATENTEUMAR 1 31915 SHEET 2 or 2 TAIPERED ROLLER RETAINER AND METHOD OFBEARING ASSEMBLY BACKGROUND OF THE INVENTION This invention relates toimproved tapered roller retainers and to simpler methods of bearingassembly utilizing the characteristics of the roller retainer.

The prior efforts to use moldable material for producing bearingretainers has generally centered around the injection molding processbecause it offers high production capability with low labor cost andsatisfactory precision even with parts having complex details. In thecase of tapered roller retainers or cages, the prior attempts have notbeen successful because, in most cases, the retainer has copied existingdesigns of roller cages and retainers made of metal. Metal retainers ofthe prior art have generally required an expensive cage-closing-inoperation and in reproducing such retainers or cages in injection moldedparts the design has had to go to retainers composed of two-parts inorder to permit insertion of the tapered rollers and effective cagingthereof.

SUMMARY OF THE INVENTION The present tapered roller retainer ischaracterized by a body having a single flange supporting caging fingersformed to provide reverse tapered pocket cages for the tapered rollers.The retainer is more particularly characterized by being a one-piecemolded body formed of glass reinforced nylon by standard injectionmolding process, and in which the reverse tapered pocket cages for thetapered rollers have the large diameter ends located at the singleflange and the small diameter ends located at the free ends of the cagefin gers. The particular advantage of a single flange retainer is thatthe cage fingers, while inclined radially inwardly to form a conicalconfiguration, may be radially displaced toward a cylindricalconfiguration to enlarge the space between the free ends of the fingersto accept the rollers without difficulty. Release of the free ends ofthe cage fingers permits the fingers to return to their originalposition effectively caging the rollers and forming an integralroller-cage assembly.

The method of effecting bearing assembly includes the steps of flexingthe retainer cage fingers to an enlarged circumferentially spacedposition whereby the free ends of the fingers are opened to receive thelarge diameter ends'of the tapered rollers, and inserting the resultingintegral roller cage assembly, flange end first, over the small diameterend of the bearing cone in a single continuous motion so that the cagefingers are momentarily flexed radially outwardly to pass over the ribat the small diameter end of the cone and snap back to cage the taperedrollers on the cone raceway.

BRIEF DESCRIPTION OF THE DRAWINGS A preferred embodiment of the presentinvention is shown in the accompanying drawings wherein:

FIG. 1 is a sectional elevational view of a roller bearing assemblyshowing the improved roller retainer in operative position with thetapered rollers between the cone and cup;

FIG. 2 is a plan view of the roller retainer with the tapered rollersassembled therein;

FIG. 3 is a fragmentary sectional view of the roller retainer taken atline 3-3 in FIG. 1;

FIG. 4 is another fragmentary sectional view of the roller retainertaken at line 44 in FIG. 1;

FIG. 5 is a sectional elevational view of the roller retainer prior toinsertion of the tapered rollers;

FIG. 6 is a sectional elevational view of the roller retainer mounted onthe roller insertion tool to flex the retainer fingers radiallyoutwardly to a generally cylindrical configuration to receive therollers; and

FIG. 7 is a sectional view of the method of ayplying the retainer androllers as a unit on to the cone to form a cone assembly.

DESCRIPTION OF THE PREFERRED EMBODIMENT In FIG. 1 it can be seen thatthe bearing assembly is composed of a cone 10 having a thrust rib 11 atthe small diameter end and a raceway 12 inwardly of the thrust rib 11. Aplurality of tapered rollers 13 are engaged on the cone raceway 12 withthe small diameter ends in running contact with the thrust rib 11. A cup14 has its raceway 15 engaged on the tapered rollers 13, and aseparately formed thrust rib 16 is mounted at the large diameter end ofthe cup 14 to guide the large diameter ends of the rollers 13.

The assembly of FIG. 1 includes the improved roller cage or retainer 17which maintains the rollers 13 in proper spaced relation around theraceways 12 and 15. The retainer 17 is a one-piece molded body having acircular base flange l8 spaced between the large diameter end of thecone 10 and the cup thrust rib 16. A plurality of fingers 19 extend fromthe flange 18 toward the small diameter ends of the rollers 13. Theretainer 17 is molded from glass-reinforced nylon so as to be flexiblefor facilitating methods of assembly to be described presently. Moldableglass-reinforced nylon provides great accuracy of molding, stability ofdimensional characteristics and reliability of operation underconditions of bearing loads and stresses. Furthermore, a single flange,one-piece retainer eliminates the usual cage-closing-in operation, andpermits installation of the retainer 17 and rollers 13 as a unit in thefinal step of effecting the cone assembly. The glass reinforced nylonmaterial permits mass producing the retainer 17 by injection moldingprocedures which results in great accuracy and dimensional reliability.

In FIG. 2 the retainer 17 and rollers 13 as a unit assembly may be seento better advantage. The retainer flange 18 supports the plurality offingers 19 in radially inwardly inclined positions but with thenecessary circumferential spacing to engage the tapered rollers 13 withthe large diameter ends of the rollers adjacent the flange 18. Eachfinger 19 is formed with its side faces 20 circularly dished or concaveto substantially match the convex and tapered body of the rollers 13caged therebetween. The fragmentary sections of FIG. 3 and 4 illustratethat the spacing between the base ends of the fingers 19 adjacent theretainer flange 18 is larger than the spacing between the fingers 19 atthe free ends. The difference in this spacing is matched to thedifference in diameter at the two ends of the tapered rollers 13. Thefinger side faces 20 are circularly formed and tapered from the flange18 toward the free ends so as to closely follow the roller taper. Theretainer 17 formed in this manner will not, when in its normalunstressed condition,receive the large diameter ends of the rollers 13between the free ends of the fingers 19.

ASSEMBLY METHODS Turning now to FIGS. 5 and 6, there is shown apreferred method of assembling the retainer 17 and rollers 13. FIG. 5shows the retainer 17 in its normal unstressed condition beforeinsertion of the rollers 13. As shown in FIG. 6, the retainer 17 ispressed over a finger expanding mandrel 21 until its flange 18 seatsupon the step 22. The mandrel side faces 23, being in the form of acylinder, expands the fingers 19 to an extent sufficiently to open thespace at the free ends of the fingers 19 to allow the large diameterends of the tapered rollers to pass between the circularly dished faces20. The insertion of the rollers 13 is facilitated by forming themandrel 21 with pockets 24 which align with the spaces between fingers19. Thus the tapered rollers 13 may be inserted in the respective spacesbetween each of the several fingers 19 with ease. When a completecomplement of rollers 13 has been inserted, a removal ring 25 is axiallyadvanced along the mandrel 21 to drive the retainer 17 and rollers offthe mandrel end, and in this removal operation the fingers return to theangularly inwardly inclined positions seen in FIG. 5, thereby caging therollers 13 in proper position between the fingers.

FIG. 7 illustrates the step in the method of installing the retainer 17and rollers 13 onto the cone 10 by pressing the retainer 17 flange endfirst over the cone small diameter thrust rib 1 1. In this operation thethrust rib 11 causes the fingers 19 to expand radially outwardly due tothe roller interference on the thrust rib 11. The insertion is easilyaccomplished in a continuous thrust motion (arrow A) to slide theretainer 17 over the rib 11 until the finers 19 can resume theiroriginal position to cage the rollers 13 against the cone raceway 12.

SUMMARY OF THE DISCLOSURE The disclosure herein presented is of a uniqueretainer of one-piece molded glass-reinforced nylon material for cagingtapered rollers in an integral retainer-roller assembly. The one-pieceretainer avoids present cage-closing-in operations, and allows a muchsimpler method of installing the assembly on a bearing cone by simplysnapping the retainer and its caged rollers over the small end rib ofthe cone. The single flange 18 form of the retainer [7 permitsinstallation of the retainer as the final step of the cone assembly.

The retainer 17 is provided with resilient fingers 19 having reversetapered roller pockets between the dished or concave faces 20 so thatthe rollers are securely caged in operating position. The resilientcharacter of the fingers l9 and the open-ended pockets allows a simplemethod of loading the rollers into the retainer by the methodillustrated in FIG. 6.

It should now appear clear from the foregoing specification that thetapered roller retainer with its open-end roller pockets formed betweencircumferentially spaced fingers has the advantage over prior rollerretainers or cages in that the fingers may be easily expanded radiallyoutwardly to open up the circumferential spacing sufficient to acceptthe rollers with the large diameter ends foremost. A simple assemblytool is all that is needed to retain the fingers of the retainer intheir circumferentially enlarged or expanded positions during theinsertion of the tapered rollers, and after the tool has been withdrawnthe fingers quickly return to normal positions effectively caging thetapered rollers and forming the desired integral retainer-rollerassembly.

It should now be understood from the foregoing specification that theintegral retainer-roller assembly is capable of speeding up the methodof assembling a complete bearing as the roller retainer can be againmomentarily flexed as it is pushed over the small end thrust rib of thebearing cone. This improved method of bearing assembly is made possiblebecause of the single flange construction of the retainer.

A characteristic advantage of the single flange tapered roller retaineris in forming the roller cage fingers to normally assume an angular orinwardly inclined position relative to the flange which will contact therollers, caging them in proper alignment, and in utilizing glassreinforced nylon material which will allow the cage fingers to be flexedradially outwardly so that the fingers may assume a generallycylindrical configuration in order to initially insert the taperedrollers and for purposes of simplifying the assembly steps in producinga complete bearing.

What is claimed is:

1. An integral tapered roller and roller retainer assembly comprisingtapered rollers and a roller retainer body being characterized by anannular base flange and circumferentially spaced roller retainer fingersextending from base ends at said base flange in a common direction toouter free ends, said fingers normally forming elements of a cone withsaid free ends circumferencially closer together than said base ends,said body being formed of material having flexibility sufficient topermit said fingers to be expanded radially into positions in which thecircumferential spacing between the outer free ends is substantially thesame as at said base ends, and each pair of fingers having opposedsurfaces adapted to cage a tapered roller therebetween against fallingout radially inwardly or outwardly of said body.

2. The retainer of claim 1 wherein said fingers are spaced apart frombase ends to free ends to form reverse tapered pockets, and said opposedsurfaces are segments of a circle of a size sufficient to cage saidrollers against skewing.

3. An integral tapered roller and roller retainer assembly comprising acomplement of tapered rollers, and a one-piece molded body for holdingsaid tapered rollers, said body being characterized by an annular baseflange and integrally formed roller retainer fingers extending from saidbase flange to outer free ends, said fingers being at the free endsradially inwardly displaced relative to the ends adjacent said baseflange to reduce the circumferential spacing between each pair offingers at the free ends to less than the circumferential spacingadjacent said base flange, said fingers collectively being capable ofbeing flexed radially outwardly to positions in which thecircumferential spacing at said free ends is at least equal to thecircumferential spacing at the ends adjacent said base flange and eachfinger having arcuately concave surfaces substantially matching thecurvature of the tapered rollers and of sufficient arcuate extent tocage the rollers to be retained thereby.

4. The roller and roller retainer assembly of claim 3 in which saidfingers are formed with opposed concave surfaces forming tapered pocketsfor the tapered rollers, said flexing of the fingers radially outwardlytransforming said tapered pockets into substantially cylin- 5 dricalpockets.

1. An integral tapered roller and roller retainer assembly comprisingtapered rollers and a roller retainer body being characterized by anannular base flange and circumferentially spaced roller retainer fingersextending from base ends at said base flange in a common direction toouter free ends, said fingers normally forming elements of a cone withsaid free ends circumferencially closer together than said base ends,said body being formed of material having flexibility sufficient topermit said fingers to be expanded radially into positions in which thecircumferential spacing between the outer free ends is substantially thesame as at said base ends, and each pair of fingers having opposedsurfaces adapted to cage a tapered roller therebetween against fallingout radially inwardly or outwardly of said body.
 1. An integral taperedroller and roller retainer assembly comprising tapered rollers and aroller retainer body being characterized by an annular base flange andcircumferentially spaced roller retainer fingers extending from baseends at said base flange in a common direction to outer free ends, saidfingers normally forming elements of a cone with said free endscircumferencially closer together than said base ends, said body beingformed of material having flexibility sufficient to permit said fingersto be expanded radially into positions in which the circumferentialspacing between the outer free ends is substantially the same as at saidbase ends, and each pair of fingers having opposed surfaces adapted tocage a tapered roller therebetween against falling out radially inwardlyor outwardly of said body.
 2. The retainer of claim 1 wherein saidfingers are spaced apart from base ends to free ends to form reversetapered pockets, and said opposed surfaces are segments of a circle of asize sufficient to cage said rollers against skewing.
 3. An integraltapered roller and roller retainer assembly comprising a complement oftapered rollers, and a one-piece molded body for holding said taperedrollers, said body being characterized by an annular base flange andintegrally formed roller retainer fingers extending from said baseflange to outer free ends, said fingers being at the free ends radiallyinwardly displaced relative to the ends adjacent said base flange toreduce the circumferential spacing between each pair of fingers at thefree ends to less than the circumferential spacing adjacent said baseflange, said fingers collectively being capable of being flexed radiallyoutwardly to positions in which the circumferential spacing at said freeends is at least equal to the circumferential spacing at the endsadjacent said base flange and each finger having arcuately concavesurfaces substantially matching the curvature of the tapered rollers andof sufficient arcuate extent to cage the rollers to be retained thereby.